150 subjects will participate in this study: 50 of which is diagnosed with depression and receive Citalopram (SSRIs); 50 depressed subjects receiving Mirtazapine(NaSRI); and 50 controls. Through randomisation half of the subjects in each group will receive daily Vitamin D supplementation for a period of one year. Through this period all 150 subjects will be followed through different measurements including bone density, muscle function and balance, nociception, quality of life and depression severity.